“It's an exciting opportunity,” he told Stephanopoulos. “To come back home, to be at a manufacturing facility, to really reconnect to what I grew up with and understood to be an America that worked, that worked for middle-income families, that created stable neighborhoods and strong families -- when you see all these reports coming out, one after another, from the far left and the far right talking about how the middle of America is hollowing out and the jobs just aren't there for the 74 percent of Americans who don't have a college degree, families are breaking down."

Santorum, 57, will formally announce his intentions at an event today in Cabot, Pennsylvania, near his childhood home.

He joins a quickly widening Republican field that already includes six declared candidates and could grow to encompass around a dozen more. Several contenders are expected to give him tougher competition this time around for the Christian conservative votes he relied on in 2012.

His experience in the last election could prove helpful, as several Republican nominees -- including Romney and Sen. John McCain, R-Ariz. -- did not clinch the ticket until their second try.

“Obviously, we learned something from the last campaign,” the Pennsylvania senator told Stephanopoulos. "Number one, we’re gonna have more money.”

“You gotta do well in Iowa,” said Santorum, who was declared the winner of the Iowa caucuses in 2012 after a 16-day delay. “You gotta win on election night as opposed to two weeks later.”

However, the competitive nature of this cycle has already thrown a hurdle in Santorum’s path, with recently released debate rules opening the possibility he will not poll high enough to participate in the first debate in August.

“It’s early,” Santorum said, when asked about the debate. “I don’t worry too much about where things are now.”